Question: An investigator wants to determine whether the difficulty of material to be learned influences the anxiety of college students. A random sample of 10 students is given both hard and easy material to learn. After part of each task is completed, anxiety levels is measured by using a questionnaire. The anxiety levels are as follows:

(a) Find the 95% CI for the difference in the population means

(b) Test whether anxiety is significantly different in the two difficulty conditions using a matched-group t-test.

(c) Redo (a) and (b) assuming two independent groups